.mainBody {
  max-width: 1200px;
  margin: 0 auto;
  .left-area {
    width: 20%;
    height:100%;
    align-self: flex-start;
    min-height:800px;
    box-sizing: border-box;
    padding:10px;
  }
  .right-area{
    width: 80%;
    overflow: hidden;
    display: flex;
    flex-wrap: wrap;
    align-self: flex-start;
  }
}